Integrated optical dual amplifier

Abstract

An apparatus is provided comprising a dual optical amplifier. The two optical amplifiers are integrated, in that they share at a set of optical, electrical, or opto-electrical components. The two optical amplifiers may share a pump laser. Alternatively, the optical amplifiers may share photo-detectors. Methods of controlling the signal strength of output signals are also provided. A chip-based integrated optical dual amplifier, using Erbium-Doped Waveguides, is also provided.

1. An apparatus comprising:
 an integrated optical dual amplifier (IODA), including:
 a first optical amplifier including a first set of components and a shared set of components, where the shared set of components includes at least a pump laser, the first optical amplifier operable to amplify a transmit optical signal; 
 a second optical amplifier including a second set of components and the shared set of components, the second optical amplifier operable to amplify a receive optical signal, the receive optical signal being distinct from the transmit optical signal; 
 a coupler coupling the pump laser to each of the first optical amplifier and the second optical amplifier; 
 a variable optical attenuator positioned between the coupler and one of the optical amplifiers; and 
 a controller configured to monitor a first signal strength of the transmit optical signal and a second signal strength of the receive optical signal and to control an output of the pump laser to adjust an output optical signal of at least one of the first and second optical amplifiers using monitored values of the first signal strength and the second signal strength. 
 
 
   
   
     2. The apparatus of  claim 1 , further comprising:
 a transmitter coupled to an input of the first amplifier, the transmitter configured to provide the transmit optical signal; and 
 a receiver coupled to an output of the second amplifier, the receiver configured to receive an amplified receive optical signal. 
 
   
   
     3. The IODA of  claim 1 , where the first amplifier includes one or more first photodetectors, each first photodetector configured to detect a strength of the transmit optical signal and the second amplifier includes one or more second photodetectors, each second photodetector configured to detect a strength of the receive optical signal. 
   
   
     4. The IODA of  claim 1  wherein the variable optical attenuator has an attenuation and is located between the coupler and the second optical amplifier, the IODA further comprising:
 means for determining a signal strength of a first output signal transmitted from the first optical amplifier; 
 means for determining a signal strength of a second output signal transmitted from the second optical amplifier; 
 means for adjusting an output power of the pump laser until the signal strength of the first output signal is at a first desired signal strength; and 
 means for adjusting the attenuation until the signal strength of the second output signal is at a second desired signal strength. 
 
   
   
     5. The IODA of  claim 4  wherein the means for determining the signal strength of the first output signal comprise means for detecting a signal strength of a diverted portion of the first output signal at a first photodetector, and wherein the means for determining the signal strength of the second output signal comprise means for detecting a signal strength of a diverted portion of the second output signal at a second photodetector. 
   
   
     6. An apparatus comprising:
 an integrated optical dual amplifier (IODA) including:
 a first optical amplifier including a first set of components, the first optical amplifier operable to amplify a transmit optical signal; 
 a second optical amplifier including a second set of components, the second optical amplifier operable to amplify a receive optical signal, the receive optical signal being distinct from the transmit optical signal; 
 a shared pump laser; and 
 a coupler coupling the shared pump laser to each of the first optical amplifier and the second optical amplifier; and 
 a controller configured to monitor a first signal strength of the transmit optical signal and a second signal strength of the receive optical signal and to control an output of the pump laser to adjust an output optical signal of at least one of the first and second optical amplifiers using monitored values of the first and second signal strengths. 
 
 
   
   
     7. The apparatus of  claim 6 , further comprising:
 a variable optical attenuator configured to adjust a pump signal from the pump laser to one of the first and second amplifiers. 
 
   
   
     8. An apparatus comprising:
 an integrated optical dual amplifier (IODA) including:
 a first optical amplifier operable to amplify a first received input optical signal received from a transmitter; 
 a second optical amplifier operable to amplify a second received input optical signal for output to a receiver; 
 a shared pump laser; 
 a coupler coupling the shared pump laser to each of the first optical amplifier and the second optical amplifier; and 
 a controller configured to monitor a first signal strength of the first optical signal and a second signal strength of the second optical signal and to control an output of the pump laser to adjust an output optical signal of at least one of the first and second optical amplifiers, using a value of one or more of the first signal strength and the second signal strength. 
 
 
   
   
     9. A dual optical communication module comprising:
 a transmission module comprising a transmitter and a booster amplifier, wherein the booster amplifier includes a first set of components and a shared set of components, and the shared set of components includes at least a pump laser; 
 a reception module comprising a receiver and a pre-amplifier, wherein the pre-amplifier includes a second set of components and the shared set of components; 
 a coupler coupling the pump laser to the booster and the pre-amplifier; and 
 a variable optical attenuator positioned between the coupler and either the booster or the pre-amplifier; and 
 a controller configured to monitor a first signal strength of a first optical signal of the transmission module and a second signal strength of a second optical signal of the reception module and to control an output of the pump laser based on monitored values of the first and second signal strengths to adjust an output optical signal of at least one of the transmission module and the reception module. 
 
   
   
     10. A method comprising:
 monitoring a first signal strength of a first optical signal in a first amplifier; 
 monitoring a second signal strength of a second optical signal in a second amplifier, the first optical signal being distinct from the second optical signal; and 
 adjusting an output power of a pump laser to adjust an output optical signal of at least one of the first amplifier and the second amplifier using monitored values of the first signal strength and the second signal strength.